The present invention relates generally to the field of cleaning a gas stream and more particularly to a method and apparatus for removing particulates and absorbing undesired gases from a gas stream and emitting a cleansed gas by mixing a gas with a liquid in an economical manner.
It is very often desirable to clean a gas stream of particulates and/or undesirable gases. Some gases, such as industrial emissions, must be cleansed or scrubbed until the emission meets legally regulated standards to be emitted into the atmosphere. Car emissions must meet legal standards, at least once a year. It is also becoming more desirable and popular to clean air in domestic settings. In fact, there are studies indicating that indoor pollution may be as great, if not a greater risk, to the individual health than outdoor pollution.
Indoor air quality is made worse by the fact that is usually entrapped and recirculated in structures that are sealed to a greater extent than in the past for energy saving reasons. The air which we inhale and exhaled is continually picking up particulates and becoming more comprised of other gases such as carbon dioxide and carbon monoxide in proportion to the oxygen and nitrogen content of the air. Domestic pollution is becoming an increasing health hazard seriously effecting the young an old, those with respiratory problems, asthma and allergies. Some of these irritants and pollutants include, but are not limited to, allergens such as pollen, mold spores, pet dandruff and dust, and gases such as carbon dioxide, carbon monoxide and naptha. Additionally, the surrounding air contains bacteria, viruses and odors that are undesirable.
Several methods are currently used to attempt to clean or partially clean gases such as air in a domestic setting. One of the most common methods of xe2x80x9ccleaning airxe2x80x9d is the utilization of filter systems. Typical filter systems for domestic use utilize a fan to circulate air from the environment through a mesh filter and at times through an additional charcoal source to absorb odors. These systems are very limited in the particulate size that is removed and only mask odors without addressing gases included in surrounding air. For these prior art systems to be even limitedly efficient it is required to frequently replace and/or clean the filters.
Other current and prior art air cleaning devices include electrostatic devices that electrically charge particles for capture. Again, this cleaners are very limited what is removed and the quantity of removal of particulate. Another drawback with electrostatic cleaning devices is that the charged dust particles that are emitted excessively collect on furniture, drapes, blinds, frames and the like.
Another type of gas cleaner requires the use of a venturi for scrubbing the gas. A venturi gas scrubber is a wet scrubber effective for removal of noxious gases, fumes, odors, particles and dust from a gas stream. Essentially, these type of scrubbers utilize a high velocity motive fluid stream passed through a constricted area to mix the gases with the motive fluid, absorb the selected gases and wet the small particulates for removal. The motive stream and mixed gas are impacted dropping out the particulates. Additionally, the undesired gases and odors are eliminated through absorption or chemical reaction between the undesired gases and the motive or scrubbing fluid. Passing the carrying gas through a mechanical cyclone may eliminate the particles. The primary deficiency in these type gas scrubbers is the pump. The pump required for the motive fluid is expensive, bulky and noisy.
It is therefore a desire to provide a method and apparatus for cleansing a gas utilizing a gas scrubbing system that reduces the pump requirements for a quantity of gas to be scrubbed. It is a further desire to eliminate the requirement of a conventional pump while mixing a liquid with a gas for scrubbing the gas.
A system and method of cleansing a gas of undesired particulate, aromas, and gases of the type utilizing a liquid to wet a gas stream is provided. The gas scrubber of the present invention including a container having a bottom wall and a top wall interconnected by a side wall containing a liquid having a surface forming a space between said surface and said top wall; a tube mounted through the top wall, the tube having a tube inlet opened exterior of the top wall connected via a throat to a tube outlet disposed in the space, the tube allowing a gas to flow from exterior the container into the space; a motor having a rotatable shaft, the motor positioned above the top wall, the shaft extending through the tube; a siphon pipe connected to the rotatable shaft, the siphon pipe having a siphon inlet disposed below the liquid surface and a siphon outlet positioned above the surface proximate the tube throat; wherein the rotating siphon pipe draws and rotates the liquid through the siphon pipe into the tube throat drawing the gas into the throat mixing with and scrubbing the gas; and a second opening formed through the container for discharging the scrubbed gas from the space exterior of the container. Undesired gases are removed from the original stream by absorption in the liquid and particulate is dropped out of the gas stream after being wetted by the liquid.
The gas scrubber may include a rotatable fan wheel attached to the shaft, the fan wheel being positioned proximate the tube inlet to introduce additional gas through the tube and into the tube throat.
The gas scrubber may further include a screw propeller attached to the shaft to rotate therewith, the propeller having blades, each having a top leading edge and a bottom trailing edge interconnected by a face with the top leading edge positioned proximate the tube inlet for introducing additional gas down the face into the tube throat.
The gas scrubber may include blades attached to a top, outside portion of the siphon pipe, each of the blades having a top leading edge and a bottom trailing edge interconnected by a face that tangentially encircles the siphon pipe; the top leading edge positioned proximate the tube inlet and the bottom trailing edge positioned proximate the throat; the siphon pipe outlet positioned proximate the top leading edge of each blade such that liquid flowing out of the siphon pipe outlet flows across the face and the rotating face forces the gas and liquid down the face to mix the liquid and gas and forcing the mixture down and centrifugally off the trailing edges through the throat to further mix and scrub the gas with the liquid in the throat.
The discharged mixture drops out particulate and the liquid absorbs selected gases. The cleansed gas may then be released to the atmosphere. The partially cleansed gas may be routed through a separating device such as mechanical cyclone to drop out additional particulate and entrained liquid.
It should be realized in conjunction with the description of the device that various elements of the invention may be utilized in numerous combinations to achieve the desired results of the invention. For example, and not for limiting purposes, the system may utilize an oblong nozzle and oblong throat in combination with a conventional pump, reducing the pumping requirements typically required by prior art devices for the same amount of gas to be cleansed and liquid for cleansing. Additionally, the conventional pump may be eliminated by use of the siphon pipe singularly or in combination with other elements described.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of a preferred embodiment of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.